Neil Young and Crazy Horse play at the United Center Thursday. (E. Jason Wambsgans/Chicago Tribune)

Frank “Pancho” Sampedro, the longtime guitarist in Crazy Horse, is a barrel of a man. He wears the look of a retired linebacker who has put on a few pounds. But he went airborne Thursday at the United Center as he and Neil Young squared off and stomped around the stage.

Instead of hunching over his guitar, bending at the waist as he normally does, Young turned his instrument into a machine gun, his legs splayed, straw hair flailing. “I (messed) up again and again,” he roared, first raging, then pained, as if he were reliving some trainwreck moment from the past.

By the end, the singer was a demon-eyed street oracle howling at the audience. “They give you this, but you pay for that,” he spat, turning “Hey Hey, My My (Into the Black)” into an Occupy manifesto.

Young and Crazy Horse have been an off-and-on proposition for more than 40 years, but Young has indisputably made some of his best – and most violent – music in the company of Sampedro, bassist Billy Talbot and drummer Ralph Molina.

Now they’re on the road for the first time in nearly a decade. A few props were resurrected from the late-‘70s “Rust Never Sleeps” tour – the giant amplifiers and parade-float-sized microphone serviced by lab-coated roadies. But that was about it for nostalgia. The quartet has released two new albums this year, and the set list Thursday brimmed with new songs, rejiggered arrangements and feverish intensity.

Make no mistake -- the past kept creeping into the songs. The passage of time and how it twists perceptions and tests relationships is a major theme in Young’s new work. Wistfulness oozed from several songs, including the 17-minute “Ramada Inn,” in which a couple finds that even love isn’t enough to keep them from drifting apart. He shuts down, she pulls away, and time rolls on.

But there was nothing particularly genteel or overly familiar and comforting about this music. Like one of Young’s beloved trains, Crazy Horse is a large beast that tends to ease into its work. But once it gains its bearings and picks up speed, it’s awfully difficult to slow down. At least five of the 13 songs performed Thursday surpassed the 10-minute mark. “Love and only Love” began like an extended exhale before finding its pace, with Young, Sampedro and Talbot huddled in front of the drum riser. Whereas most bands spread out to fill a big stage such as the United Center’s, Crazy Horse bunches together, as if defending their home against invasion.

The group works itself into a trance-like frenzy, Young’s guitar piercing through a thicket of bottom-heavy tones and rumbling drums. For the relatively pithy “Cinnamon Girl,” the feedback that shut it down lasted nearly as long as the song itself. The band turned the period psychedelia of Young’s old Buffalo Springfield hit “Mr. Soul” into churning acid-punk. Molina’s drums on “Hey Hey, My My (Into the Black)” pumped like pistons in a factory.

Normally, the encore is a time of a celebration, of release. But Young and Crazy Horse instead shook loose the ghosts of the harrowing “Tonight’s the Night.” Expanded to 10 minutes, the song became a long, lonely howl for fallen friends, a séance. “Tonight’s the night,” Young whispered. “Yes, it is.”

greg@gregkot.com

Neil Young and Crazy Horse set list Thursday at United Center:1 Love and Only Love2 Powderfinger3 Born in Ontario4 Walk Like a Giant5 The Needle and the Damage Done6 Twisted Road7 Untitled new song 8 Ramada Inn9 Cinnamon Girl10 (Expletive) Up11 Mr. Soul12 Hey Hey, My My (Into the Black)